Geophysical Examination of the Christian Archaeological Site Emmaus-Nicopolis (Central Israel)
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GEOPHYSICAL EXAMINATION OF THE CHRISTIAN ARCHAEOLOGICAL SITE EMMAUS-NICOPOLIS (CENTRAL ISRAEL) L. V. Eppelbaum a, *, S. E. Itkisb aDept. of Geophysics and Planetary Sciences, Raymond and Beverly Sackler of Exact Sciences, Tel Aviv University, Ramat Aviv 69978, Tel Aviv, Israel - [email protected] bDept. of Geological and Environmental Sciences, Ben Gurion University of the Negev, Be’er-Sheva, Israel - [email protected] KEY WORDS: Archaeology, Geophysics, Surveying, Application, Mathematics, Development, Interpretation, System ABSTRACT: Christian archaeological site Emmaus-Nicopolis is well known in the ancient and Biblical history. The site located halfway between Jerusalem and Tel Aviv, first built in the 5th century, over the site believed to be the place where Jesus appeared to two of his disciples after his resurrection. The Crusaders rebuilt it on a smaller scale in the 12th century. Two sites were examined by detailed magnetic investigations: (A) 25 x 40 m and (B) 10 x 24 m. Distance between the observation points was 1 meter, but not all points were accessible due to dense vegetation and rugged topography. Quantitative interpretation of magnetic anomalies was conducted using modern quantitative methods specially developed for complicated environments: oblique magnetization, rugged terrain relief and unknown level of the normal field. A distinct peculiarity of the survey was the fact that from these areas an upper part of soil (about two meters) containing modern contamination targets has been recently removed. A primary aim of this investigation was detection of buried ancient tunnels partially discovered at the eastern part of Emmaus-Nicoplis. However, performed survey allowing to revealing at least three high-intensive positive anomalies at the area A and one significant anomaly at the area B. Thus, all revealed anomalies (after removing 2m soil) must reflect some buried ancient remains. Determined depth of the upper edge of anomalous sources ranges from 0.7 to 1 m. Reliability of performed quantitative interpretation was successfully confirmed by 3-D modeling of magnetic field. The obtained results (they may have a great archaeological importance) were transmitted to archaeological group working at this site. The proposed ancient targets will be archaeologically inspected at the nearest time (apparently, until October 2003). 1. INTRODUCTION estimate the possible archaeological significance of the area under study. Rapid (first results may be obtained during a few The territory of Israel, in spite of comparatively small hours − several days) and reliable interpretation of magnetic dimensions (21,000 km2), is very attractive for archaeologists data should provide protection of archaeological remains from taking into account its dramatic ancient and Biblical history. It unpremeditated destruction. is undisputable fact that location of archaeological sites at Interpretation of magnetic surveys in Israel is complicated by a Israeli territory is the densest in the world (for instance, Meyer, strong oblique magnetization of the Earth’s magnetic field 1996; Reich, 1992). Christian remains consist of significant (about 42-44o). The multi-layered and variable structure of the part of the total number of discovered archaeological objects. upper part of the geological section (Dan, 1988; Rabikovitz, The Christian remains, according to the accomplished 1992) often does not allow calculating the level of the normal experience, occur in the subsurface layer at depth from 0 to 3 magnetic field within the studied sites. Noise caused by meters and often hold their initial correct (quasi-correct) industrial iron and iron-containing objects sometimes reaches geometrical form. Detailed magnetic survey is successfully high values. Rugged relief also disturbs the effect from the applied to searching and localization of the remains, as rapid, buried objects and complicates quantitative interpretation of effective and non-invasive tools for revealing a broad range of magnetic anomalies (Eppelbaum and Khesin, 2001). The various targets: buried walls, columns, foundations, complicated conditions of the survey require application of underground tunnels, chambers, water pipe systems and high sophisticated magnetic equipment, advanced methods of temperature features (Dalan, and Banerjee, 1996; Eppelbaum, qualitative and quantitative interpretation as well 3-D modeling 2000; Frese and Noble, 1984; Herwanger et al., 2000; of magnetic field. The developed methods (Eppelbaum et al., Weymouth, 1996). Geophysical surveys provide a ground plan 2000b; Khesin et al., 1996) allowed to eliminate noise, to reveal of cultural remains before excavations or may be even used archaeological remains and calculate their depth and size, and instead of excavations. Road and plant construction, selection to conduct an accurate 3-D modeling of magnetic fields. of areas for various engineering and agricultural aims are usually accompanied by detailed geophysical (first of all, Eppelbaum et al. (2003b) have shown an importance of correct magnetic) investigations. Such investigations should help mathematical formalization of geophysical/archaeological * Corresponding author. consequently Objects archaeologists havetroubles experience followsthatmajority notion examination. 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C.E. theEm Christian 12th resurrection. TheCrusadersrebuiltitona the placewhereJ Aviv, shown in theancientandBiblicalhis Christian archaeologicalsite Figure 2.Exposedremainsofwallsinthecentralpart prim century 2. first in NICOPOLIS ARCHAEOLOGICALSITE ary BRIEF DESCRIPTIONOFTHEEM Figure Pilgrim textsfromthe4thcentury built peror ElagabalusgaveEm (May aim in 2) e ofm s er, 1996).Nicopolisisassumedinalmostall the u located halfway Em s appearedtotwoofhis 5th century m a gnetic investigationsatthissitewas a us-Nicopolis site Emmaus-Nicopolis iswell y t ory changed duringthefield , overthesitebelievedtobe betweenJerusalemandTel . Thesite(itsfragm m a us thetitleof sm dis onward.In221 aller investigated c M iples AUS- scale after city known ent is in and the his at 3.2 Quantitative interpretation of magnetic anomalies 3. MAGNETIC EXAMINATION OF TWO SELECTED AREAS AT THE SITE OF EMMAUS-NICOPOLIS This stage involves application of methods for quantitative interpretation of magnetic anomalies for development of an 3.1 Methodology of field magnetic observations initial physical/archaeological model. The developed methods The magnetic survey at the site of Emmaus-Nicopolis have 0 4 been carried out using following equipment: , m • Proton Magnetometer MMP-203 (Era Assoc., Sankt- Petersburg, Russia), No. 206033 (it was used for field ance Dist observations), 35 • Quantum Magnetometer MM-60 (Era Assoc., Sankt- Petersburg, Russia), No. 207001 (it was used for registering temporary magnetic variations at control point), 30 • Kappameter KT-5 (Scintrex, Canada) for magnetic